Excavating tooth point retaining device



INVENTOR. @zzm Q/ww/c Ill G. F. DROVER EXCAVATING TOOTH POINT RETAINING DEVICE Filed April 15, 1956 March 8, 1960 United States Patent i EXCAVATING TOOTH POINT RETAININ G DEVICE Glenn F. Drover, Riverside, Ill., assignor to American Steel Foundries, Chicago, lll., a corporation of New Jersey Application April 13, 1956, Serial No. 577,983

8 Claims. (Cl. 37142) This invention relates to excavating teeth of the type adapted for use on the cutting edges of scoops, buckets, dippers and other excavating equipment and particularly to a tooth having a separate base and point keyed to each other in telescopic relationship.

The invention comprehends a novel safety retaining devicev operable to prevent the accidental displacement of a wedge key in the event that it becomes loosened.

A highly undesirable feature incidental to the use of wedge keys as securing means is that, after relatively short periods of operation, they tend to loosen and work their way out of the slots of secured members, with the result that the members separate from each other. Various ways have been devised to insure the retention of wedge keys in slots of secured members, such as the use of cotters or auxiliary keys extending through the keys, but the complexities of most of these arrangements have rendered them impractical from the standpoint of cost and operation. A few of these arrangements have utilized resilient keys or resilient devices compressibly engaging the keys. A common disadvantage of these arrangements has been that the pressure exerted by the compressed device against the key tends to urge the key away from engagement with the members causing it to work loose.

Another problem constantly arising in connection with the use of auxiliary key retaining devices is that of removal of the key and retaining device. After a tooth has been in operation for a brief period of time, pieces of the material being excavated become lodged in the slots of the tooth members with the result that removal of the key and retaining device becomes virtually impossible. Even where a resilient block is disposed between the key andl one of the tooth members, entry ofthe foreign matter rapidly causes the slot to be filled to the extent that, because the resilient block has no room for deformation or expansion, it not only fails to serve its purpose, but actually prevents removal of the key.

It is therefore a primary object of this invention to provide a practical key retaining device of simple operation and construction which will function successfully at all times and under all operating conditions.

It is another object of the invention to provide a key retaining device which will accommodate removal of the key even when the slot in which the key and retaining device is disposed is filled with foreign matter.

Another object of the invention is the provision of a key retaining device which can be housed substantially within the key itself and inserted into the slots of the members at the same time the key is inserted.

A further object of the invention is to provide a resilient key retaining device noncompressibly disposed in a cavity of the key.

Still another object is the provision of a resilient key retaining device capable of internal expansion so as to be operable under all conditions.

A more specific object of the invention is the provision of a key retaining device comprising a resilient block 2,927,387 Patented Mar. 8, 1960 having a passageway extending therethrough to permit its internal expansion and a nonresilient clip capable of retaining said block in proper position within the tooth.

These and other objects of the invention will be apparent from the examination of the following description and accompanying drawings, wherein:

Figure l is a fragmentary sectional view, taken along line 1-1 of Figure 2, illustrating a portion of an excavating tooth assembly embodying features of my invention;

Figure 2 is a fragmentary sectional view taken along line 2 2 of Figure l;

Figures 3 through 5 are detailed top plan, side elevational and front elevational views, respectively, of the wedge key retaining assembly block.

it will be noted that certain elements have been intentionally omitted from certain views where they are better illustrated in other views.

Referring now to the drawings for a better understanding of the invention, and particularly to Figures 1 and 2, it will be seen that the excavating tooth comprises a base indicated generally at 10, having a forwardly extending substantially wedge shaped nose portion 12 telescopically received in a complementally shaped pocket 14 of a removable point indicated generally at 16.

As illustrated in the drawings,.the base and point are preferably formed symmetrically abouttheir vertical and lateral center planes in order that they may be reversible either individually or jointly.

The base nose 12 presents parallel side surfaces 18 interconnected by forwardly converging upper and lower inclined surfaces 20 and spaced parallel upper and lower shelf surfaces 28 which blend into an arcuate forward surface 22.

The surfaces 20 may be recessed, as at 24, to present a pair of vertically spaced upper and lower shelf surfaces 26 disposed in planes parallel -to each other and to the lateral center plane of the tooth and parallel to shelf surfaces 2S. The spaced parallel surfaces 26 actually function in two ways to aid in keeping the base and point members in assembled relation. First, because they'are parallel, they do not tend to exert wedging pressures which would tend to force the members apart as would 'diverging surfaces; and second, in the event a securing key is accidentally withdrawn, the parallel surfaces actually serve to temporarily retain the members together for to become separated the members would have to be moved away from each other while in almost perfect vlongitudinal alignment.

VThe point and base members are provided with ooaligned preferably rectangular slots 30 and 32, respectively, Which extend through the respective members in a direction substantially normal to the lateral center plane of the tooth. y

To secure the base and point members in telescopic relationship to each other, a key 34, preferably formed of metal and wedge shaped with a straight rear surface 36 and a rearwardly sloping forward surface 38, is disposed in the slots of the respective members with the rear key surface 36 in nonresilient metal-to-metal surface contact with the rear walls 40 of the point slots 30 and the forward key surface 38 in direct nonresilient surface engagement with the forwardwall 42 of the nose slot 32. it will be noted that the forward wall 42 is slightly V-shaped, as seen in elevation, in order to accommodate the reversal of positions of the nose relative to the wedge key. y

Key 34 is provided adjacent its rear surface 36 with a channel or cavity 44 extending transversely therethrough and having a forward surface 46 which is preferably inclined with respect to the upper and lower surfaces 48 of the key channel. A shoulder or lip 50 formed on the key adjacent the channel 44 serves to enclose the lower lportion of channel 44. The function Y of this channel is to house a wedge key safety retaining assembly indicated generally `at 52, the details and function of which are hereinafter described.

Xin order to insure the retention of; key 34 in position within the co-aligned slotsof the tooth members, a key safety retaining devic'eindicated generally at 52 is provided and' preferably` disposed substantially within the key channel 44 for engagement between the key and then inserted-into the aligned slots 30 and 32Y of the As best seen in Figure 2, the retaining device 52 corn-` f prises a resilient pad or block 54 and a metal clip Se.

The block 54 is preferably formed of a readily deiormableV material such as rubber and, Vas illustrated in Figures 3-5, may be generally 'trapezoidal' vertical section having parallel top and bottoni surfaces 58 and upwardly diverging front and rear lsurfaces 60 and 62, respectively. Additionally, the block -is provided with a preferably rectangular opening or passageway 64 eXtending therethrough from the front tothe rear surface, the function of the passageway being hereinafter described.

The clip may be Vformed of metal and generally V-shaped as seen inside elevation comprising a pair of substantially flat integral upper and side arms 66 and 63,

respectively, which diverge-'to form an inner angle therebetween of less than 90 degrees, the upper arm preferably being less than half the length of the side arm.

When the vtooth is completely assembled, the-retaining device is snugly positioned in the' key channel 44 with the forward and bottom surfaces 6G and 58 of the block 54 in abutting engagement with the'forward and lower surfaces 46 and 48, respectively, of the channel 44 andV the rear surface 62 oi the'block in abutting engagement with the forward or inner surface 72 of the Aclip side arm 63. Before Ythe tooth is assembled, the device 52 is retained in ,the key'jchannel by the engagement of clip arm-66 withrsurface A4S and by engagement of the clip side arm 68 with the lip 50 as at '76. After assembly of the tooth, the engagement between clip surface 70 and the rear wall 43 of the base nose slot as at 74 serves to maintain the elements of the device S2 in snug engagement Vwith each other and with the key and base member. Although the parts of the device are of such dimensions as to preclude clearance betweenl the elements and the key' and base member, the block is preferably under no appreciable compression. Y l

With this snug iit, it will be seen that the iront and rear entrances to block'passageway 64 are closed thereby preventing the entrance of foreign matter into the passageway. 'I'hus when the tooth is in operaton'and foreign matter becomes lodged around the retaining device, the open passageway affords room for internal expansion of the block to permit its compression for removal of the key when desired.

It will also be understood Vthat because the engagement between the angle shaped clip and key lip Sti serves -to maintain Ythe block and'cli'p in firm contact with each Y other. and retain both elements of the retaining device within the keychannel, the necessity for having the elements bonded or otherwise'permanently secured together is eliminated lthereby further reducing thecest of construction. t r a To assemble the device, the base nose is inserted in the point pocketV with the inclined surfaces 2t) of the nose in Ysurface engagement with the inclined surfaces 29 VVofy the pocket and with the nose slot 32 in substantial alignment with the point slot 30. Retaining assembly 52 is then inserted into the key channel 44 with the block 54A and theclip 56 retained in the key channel by the 'lip S0 n the position as above described. The key is nose until the forward andV rear surfaces' 38 and 36 of the key are in metal-to-metal surface contact with the Vforward and rear surfaces 42 Vand 40 of the nose and point slots 32 and 30, respectively, and the rear surfaces 7i) of the clip side arm 68. engaging the rear wall 43 of the nose slot.

Although the block must be compressed in order to permit the insertion or removal of the key and retaining device from the toothmember'slots, the Vblock is'prefer- "ably not under any appreciable compression while in vpurpose ofthe wedge keyitself. ,Y In order to disassemble the device, pressure is V@averted upon the bottom of the key to force lit upward and out of the slots. A camming action takes place between the cam surfaces 80 and 82 of the tooth point slot rear wall 30 and the outer side of the clip 56, respectively, which serves to compress the retaining device and permit withdrawal of the key.

I claim: Y

l. In an excavating tooth-having aY removable point member with a pocket therein and a base member having a nose telescopically disposed in the pocket of said point, the combination of: a downwardly tapered wedge key disposed in aligned slots of the respective members and operable to secure said members to eachother in telescopic engagement, said key presenting a channel extending laterally therethrough and having a lip thereon adjacent said channel, said key havingvnonresilient surface contact with one of said members at two places and with the other member at one place intermediate said two places, and a resilient wedge key safety retaining device disposed in said key channel` in-noncompessed abutting engagement with said key and said other mernl'er,v said device comprising a resilient block capable of internal expansion snugly positioned adjacent said key and a separate metal clip snugly disposed between said block and Vsaid'other member, said lipbeing operable to retain said tween the clip and one of the members belngeperable device to facilitate the withdrawal of the key from the slots of the members, wherein said block is substantially trapezoidal, as seen in side elevational view, and wherein said clip, as seen in side elevational view comprises a lpair of integral arms, one being at least twice as long 'as the other, which diverge tol form an acute angleVv therebetween.-

' 2. In an excavating tooth, having arremovable point member with a pocket therein and having arbase member with a nose telescopically disposed in said pocket, the combination of: a wedge key disposed in aligned slots of the respective members and in rigidnonresilient wedge contact with both members to secure said members to each other, said key having a channel extending laterally therethrough and having a lip thereon adjacent said channel, and a resilient wedge key saiety device disposed in said channel in substantially non'compressed abutting en gagement with said key and said baise4 member, said device comprising a resilient .block snugly disposed against tne key and comprising metal clip snugly positioned against said block and against said base member, said lip being engageable with 'the clipk to retain said in said channel during insertion of the vkey into the slots of said members, and Vspaced carnrrrng means on therclip andv one of the members, respectively, `said camming means being interengageable to compress the block upon withdrawal of the key from the slots; said block having an internal' cavity toV permit its internal expansion when compressed' and said cavity bein-g closed at the ends thereof by abutment of the block with said key and clip to prevent the entrance of foreign matter into said cavity.

3. An excavating tooth comprising a rigid base having a forwardly tapered nose defined by top and bottom converging surfaces, a rigid point having an internal forwardly tapered socket within which said nose surfaces are tightly wedged. apertures through said nose and point, the nose aperture intersecting said surfaces, a key having an edge in tight rigid abutment with an area of the nose in its aperture, said area facing the base, said key having another edge converging downwardly with respect to the first mentioned edge toward the center of said apertures, said other edge having tight rigid contact with the point along areas thereof facing the nose area, a resilient key retainer recessed within the key and engaging an area of the base facing said nose area, said retainer and point having upwardly and downwardly facing cam means, respectively, the cam means being spaced from each other and interengageable to compress the retainer when the key is driven from said apertures, whereby the rigid engagement of the key edges with the point areas and with the nose area prevent compression of the retainer except during assembly and disassembly of the key.

4. An excavating tooth comprising a rigid base having a forwardly tapered nose defined by top and bottom converging surfaces, a rigid point having an internal forwardly tapered socket within which said nose is tightly wedged, apertures through said nose and point, a key having an edge in tight rigid abutment with an area of the nose in its aperture, said area facing said base, said key having another edge converging downwardly with respect to the iirst mentioned edge toward the center of said apertures, said other edge having tight rigid contact with the point along areas thereof facing the nose area, a resilient key retainer recessed within the key and engaging an area of the base facing said nose area, said retainer and point having upwardly and downwardly facing cam means, respectively, spaced from each other and interengageable to compress the retainer when the key is driven from said apertures.

5. An excavating tooth comprising a rigid base having a forwardly tapered nose, a rigid point having an internal forwardly tapered socket within which said nose is tightly wedged, apertures through said nose and point, a key having an edge in tight rigid abutment with an area of the nose in its aperture, said area facing said base, said key having another edge converging downwardly with respect to the iirst mentioned edge toward the center of said apertures, said other edge having tight rigid contact with the point along areas thereof facing the nose area, a resilient key retainer disposed within a recess of the key, and means on the key and retainer for retaining the latter Within said recess when the key is removed from said apertures, said retainer comprising an internal expansion chamber substantially closed from the atmosphere to permit compression of the retainer upon removal of the key even though the recess is tightly packed with foreign matter around the retainer.

6. A wedge key and retainer assembly for maintaining a pair of telescoping excavating tooth base and point members in tight engagement with each other comprising a. key having converging wedge surfaces, one of said key surfaces having tight metal-to-metal contact with one of said tooth members at two places spaced from each other, the other of said key surfaces having tight metalto-metal contact with the other of said tooth members at a place located between said two places, a recess in one of said surfaces, a clip in said recess and separable with respect to said key, said clip having legs engageable with the key at opposed points in its recess to retain the clip in assembly therewith, a resilient mass between the key and clip in said recess, a closed internal passage in said mass to accommodate compression thereof when the recess is completely packed with foreign matter, and cam means on said clip on the external sides of said legs at their juncture with each other, said cam means projecting outwardly of the recess to engage an associated member and thereby compress said mass as the key is removed from association with said member.

7. A wedge key and retainer assembly for maintaining a pair of telescoping excavating tooth base and point members in tight engagement with each other comprising a key having converging wedge surfaces, one of said key surfaces having tight metal-to-metal contact with one of said tooth members at two places spaced from each other, the other of said key surfaces having tight metalto-metal contact with the other of said tooth members at a place located between said two places, a recess in one of asid surfaces, a clip in said recess and separable with respect to said key, said clip having legs joining each other and defining at their juncture a cam surface disposed outwardly of said recess, said legs being engage able with the key at spaced points in its recess to retain the clip in assembly therewith, a resilient mass between the key and clip in said recess, a closed internal passage within said mass to accommodate compression thereof when the recess is completely packed with foreign matter, said recess being closed at one end by the key and at the other end by the clip and being otherwise spaced from the perimeter of said mass.

8. A wedge key and retainer assembly for maintaining a pair of telescoping excavating tooth base and point members in tight engagement with each other having converging surfaces, one of said key surfaces having tight metal-to-metal Contact with one of said tooth members at two places spaced from each other, the other of said ey surfaces having tight metal-tometal contact with the other of said tooth members at a place located between said two places, a recess in one of the surfaces, a clip in said recess movable with respect to'said key, said clip having interconnected arms arranged at an acute angle with each other and engageable with the key at spaced points in its recess to retain the clip in assembled relationship therewith, and resilient means in said recess compressible between the key and the clip, said arms having external surfaces at their point of connection forming a cam surface above the resilient means and outwardly of the recess.

References Cited in the le of this patent UNITED STATES PATENTS 1,890,981 Finkl Dec. 13, 1932 2,050,014 Morrison Aug. 4, 1936 2,259,456 Crawford Oct. 21, 1941 2,328,378 Dudley Aug. 31, 1943 2,427,651 Baer Sept. 23, 1947 2,483,032 Baer Sept. 27, 1949 2,733,915 Dentler Feb. 7, 1956 2,772,492 Murtaugh Dec. 4, 1956 

